Retrofit --A type-safe HTTP client for Android and Java

• 目前为止已经基本可以使用了，但业务需求需要统一增加header，然后又一个深坑来了，官网只有一句话
  “Headers that need to be added to every request can be specified using an OkHttp interceptor.”
• 经过两天的调试终于写好了顺便加了优雅的日志输出
  （日志输出参考自：http://stackoverflow.com/questions/28696964/okhttp-how-to-log-request-body）
• 不多说上代码（代码是谁？）

• 首先在Retrofit生成接口Engine的实现增加

  .client(TWLOkHttpClient.getOkHttpClient(this))//通过okHttp拦截器设置Retrofit的公用头部和日志输出

• 然后创建okHttp拦截器

  // Retrofit2.0只能通过okHttp拦截器设置Retrofit的公用头部
    // Retrofit2.0取去掉了日志功能也需要在okHttp里打印日志
    client.networkInterceptors().add(new Interceptor() {
        @Override
        public com.squareup.okhttp.Response intercept(Interceptor.Chain chain) throws IOException {
            Request request = chain.request();
            Request.Builder requestBuilder = request.newBuilder();
            Request signedRequest = requestBuilder
                    .addHeader("Source", "1")
                    .addHeader("Channel", AppUtil.getChanel(context))
                    .addHeader("IMEI", AppUtil.getImeiCode(context))
                    .addHeader("UserId", QicheChaorenApplication.getInstance().getUserId() + "")
                    .addHeader("Version", AppUtil.getAppVersionName(context))
                    .addHeader("Net", "" + NetWorkUtil.getNetWorkType(context))
                    .addHeader("Token", TOKEN)
                    .addHeader("SessionId", "" + QicheChaorenApplication.getInstance().getSessionId())
                    .build();
            long t1 = System.nanoTime();
            Response response = chain.proceed(signedRequest);
            long t2 = System.nanoTime();
            MediaType contentType = null;
            String bodyString = null;
            if (response.body() != null) {
                contentType = response.body().contentType();
                bodyString = response.body().string();
            }
            // 请求响应时间
            double time = (t2 - t1) / 1e6d;
            switch (request.method()) {
                case "GET":
                    Logger.d("retrofit-->", 
                        String.format("GET " + F_REQUEST_WITHOUT_BODY + F_RESPONSE_WITH_BODY, 
                        signedRequest.url(),
                        time, 
                        signedRequest.headers(),
                        response.code(),
                        response.headers(), 
                        stringifyResponseBody(bodyString)));
                    break;
                case "POST":
                    Logger.d("retrofit-->", 
                        String.format("POST " + F_REQUEST_WITH_BODY + F_RESPONSE_WITH_BODY,
                        signedRequest.url(), 
                        time,
                        signedRequest.headers(), 
                        stringifyRequestBody(signedRequest), 
                        response.code(), 
                        response.headers(), 
                        stringifyResponseBody(bodyString)));
                    break;
                case "PUT":
                    Logger.d("retrofit-->", 
                        String.format("PUT " + F_REQUEST_WITH_BODY + F_RESPONSE_WITH_BODY, 
                        signedRequest.url(), 
                        time,
                        signedRequest.headers(),
                        signedRequest.body().toString(),
                        response.code(), 
                        response.headers(), 
                        stringifyResponseBody(bodyString)));
                    break;
                case "DELETE":
                    Logger.d("retrofit-->", 
                        String.format("DELETE " + F_REQUEST_WITHOUT_BODY + F_RESPONSE_WITHOUT_BODY, 
                        signedRequest.url(), 
                        time, 
                        signedRequest.headers(), 
                        response.code(), 
                        response.headers()));
                    break;
            }
            if (response.body() != null) {
                // 深坑！
                // 打印body后原ResponseBody会被清空，需要重新设置body
                ResponseBody body = ResponseBody.create(contentType, bodyString);
                return response.newBuilder().body(body).build();
            } else {
                return response;
            }
        }
    });

• 最后来一份删除加油卡的日志（公司网络差用了2169.3ms）：

 D/retrofit-->: ╔═════════════════════════════════════════════
D/retrofit-->: ║ POST  http://192.168.2.126:9775/user/fuelcard/delete in 2169.3ms
D/retrofit-->: ║ Content-Type: application/x-www-form-urlencoded
D/retrofit-->: ║ Content-Length: 9
D/retrofit-->: ║ Host: 192.168.2.126:9775
D/retrofit-->: ║ Connection: Keep-Alive
D/retrofit-->: ║ Accept-Encoding: gzip
D/retrofit-->: ║ User-Agent: okhttp/2.5.0
D/retrofit-->: ║ Source: 1
D/retrofit-->: ║ Channel: 1000
D/retrofit-->: ║ IMEI: 隐藏
D/retrofit-->: ║ UserId: 107001249
D/retrofit-->: ║ Version: V1.3.1
D/retrofit-->: ║ Net: 1
D/retrofit-->: ║ Token: 隐藏
D/retrofit-->: ║ SessionId: 隐藏
D/retrofit-->: ║ body: cardId=41
D/retrofit-->: ║
D/retrofit-->: ║ Response: 200
D/retrofit-->: ║ Date: Fri, 23 Oct 2015 08:56:38 GMT
D/retrofit-->: ║ Content-Type: application/json; charset=UTF-8
D/retrofit-->: ║ Transfer-Encoding: chunked
D/retrofit-->: ║ Server: Jetty(9.2.1.v20140609)
D/retrofit-->: ║ OkHttp-Selected-Protocol: http/1.1
D/retrofit-->: ║ OkHttp-Sent-Millis: 1445590595631
D/retrofit-->: ║ OkHttp-Received-Millis: 1445590597800
D/retrofit-->: ║ body: {"code":0, "msg":""}
D/retrofit-->: ║
D/retrofit-->: ╚═══════════════════════════════════════════════

此为blog备份，原地址：http://blog.yzapp.cn/Retrofit1.html